Low-Complexity Digital Predistorter for MIMO Transmitters with Nonlinear Crosstalk

Two novel models with lower complexity are proposed for linearization of 2×2 MIMO transmitters with nonlinear crosstalk. Crossover modified memory polynomial (COMMP) model is introduced as an extension of the 2-D modified memory polynomial (2-D MMP) model and COMMP-CPWL model is derived from the COMMP model but without high-order terms which are replaced by the canonical piecewise linear function. Genetic Algorithm (GA) is used to achieve optimal digital predistortion (DPD) performance and least-square (LS) algorithm is adopted to extract the models coefficients. Experimental results show that both models can achieve nearly the same DPD performance and model accuracy as the 2×2 Parallel Hammerstein (PH) model while requiring fewer model coefficients.